Presently, it is known that the ISM bands are becoming crowded, with many different types of wireless devices, among those being WiFi (802.11), BlueTooth (802.15.1), and Zigbee (802.15.4), cordless phones, and others. It is understood that when these devices operate in close proximity, interference between the devices may cause performance loss, or severe degradation for particular devices. In some cases, one particular device may be rendered inoperable, and lose wireless connectivity completely. There is a need in the industry for these devices to share the limited band so that all devices may function properly, and most desirably, with little or no performance degradation.
One particularly concerning interference problem is known to occur between existing non 802.11 devices such as Blue Tooth and Zigbee devices, and WiFi devices based on the upcoming 802.11n standard, which allows devices to operate at 40 MHz wide channels. A 40 MHz WiFi channel overlaps excessively with the Non 802.11 channel, and can interrupt Non 802.11 operation. Although the Non 802.11 is equipped with interference avoidance schemes like Adaptive Frequency Hopping (AFH), a wide bandwidth of 40 MHz WiFi channel will cause this mechanism to fail, and Non 802.11 performance to degrade. This occurs because the overlap with a 40 MHz WiFi channel can block out up to 75% of the Non 802.11 bandwidth. This particular problem is of great concern because of the deployment of WiFi and Non 802.11 devices is so widespread across the world.
A potential coexistence issue has been identified between Non 802.11 wireless devices (IEEE 802.15.1) and IEEE 802.11n in WiFi products, operating in the 2.4 GHz ISM band. An 802.11n STA operating with 40 MHz wide channels can degrade the performance of Non 802.11 headsets. One possible coexistence solution is for the 802.11n device to scan for the presence of non-802.11n devices, and switch to 20 MHz operation to avoid this conflict.
Industry standards often require interoperability, whenever possible, between different devices operating in the same frequency band. To avoid interference, devices will reduce transmit power levels, or move to a different channel in the band, or time-share the same channel. For the particular problem of WiFi/Non 802.11 interference, both devices have been shown to coexist, provided the WiFi device can properly detect the presence of a Non 802.11 device and appropriately limit operation to 20 MHz bandwidth. With the operation limited to 20 MHz, the Non 802.11 AFH feature enables the Non 802.11 device to operate in the remaining bandwidth, and avoid interference with the WiFi transmissions. This particular method of detecting the presence Non 802.11 devices, and backing off to 20 MHz operation to allow coexistence is recommended in the discussions at IEEE 802.11n standard (Draft 6.0).
Therefore, it is highly desired to be able to provide a solution which overcomes the shortcomings and limitations of the present art and more particularly provides a configurable non 802.11 detection and avoidance method and system for wireless devices.
The present invention in accordance with its various implementations herein, addresses such needs.